Singer Mariah Carey yesterday said she has beefed up her personal security after fellow judge Nicki Minaj allegedly threatened to shoot her at an “Idol” audition this week in Charlotte, NC.

And Minaj immediately jumped on Twitter to mock and sneer at Carey.

“I guess it hurts 2 have the producers tell u to ur face that nicki is the best judge we’ve had since simon,” Minaj posted. “Awww, poor u. Keep them lies [coming].”

The heated and increasingly ugly feud between the two new “Idol” judges seemed to have died down by yesterday — two days after a crude video of Minaj cursing out Carey and walking off the set while taping a session was leaked online.

Then, on “The View” yesterday, Barbara Walters told viewers that she had just gotten off the phone with Carey and that the singer had said the fight was far from over.

“She said that when Nicki walked off the set, multiple people heard Nicki say, ‘If I had a gun, I would shoot the bitch,’ ” Walters told viewers reading off her notes from the phone call.

“She said there were staff members who heard, producers, other people. She said she’s very concerned. She’s with her twins.

“She doesn’t feel anything would happen, but Nicki is unpredictable and Mariah says she can’t take a chance and she’s hired extra security.

“They’ve since been together at meetings with producers and judges . . . After the meeting, Nicki said to Mariah, ‘I love you, but we might fight again.’

“Mariah responded, ‘No, we will not.’

“Mariah said she doesn’t feel comfortable emotionally, but she will continue with the show because she loves the show,” Walters said.

By the end of the show, Minaj began firing off a series of sputtering tweets — at one point, tweeting new messages every two or three minutes — implying that Carey had lied to Walters about the gun remark.

“Not even the producers believed u,” she wrote.

Other celebs even took sides in the feud. “Jersey Shore” star Snooki tweeted: “American Idol should be interesting … Nicki or Mariah? Nicki 100%.”